Half to alfred chadwick



G. J. LAVIGNE.

HIGRUMETEB GAGE. (Applicntion led A-pr. 21, 1898.)

(nu nodal.)

wz mms mths ca. Ppmuwm WASHINGTON, D. c,

adapted to be used in measuring.

UNITED STATES PATENT OEEICE.4

GEORGE J. LAVIGNE, OF NEWlv HAVEN, CONNECTICUT, ASSIGNOR OF ONE- HALF TO ALFRED CHADWICK, OF SAME PLACE.

IVIICROMETER-GAGE.

SPECIFICATION forming part of Letters Patent No. 620,337, dated February 28, 1899.

Application led April 2 l, 1 89 8.

To all whom it may concern:

Be it known that I, GEORGE J. LAVIGNE, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improvement in lVIicrometer-Gages; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in-

Figure 1, a view in side elevation of one form which a micrometer-gage embodying my invention may assume, the gage being shown as closed; Fig. 2, a corresponding view showing the gage open; Fig. 3, an enlarged View of the gage in central longitudinal section; Fig. 4, a detached view of the outer measuring-disk, the bar, and the measuring-screw; Fig. 5, a detached view of the inner measuring-disk and the graduated sleeve; Fig.v 6, a detached View of the compensating nut; Fig. 7, a detached view of the rotatable thimble; Fig. 8, a detached view of the binding-screw, and Fig. 9 a face view of the inner measuringdisk.

My invention relates to an improvement in that class of micrometer gages which are adapted for making both inside and outside measurements, the object being to produce at a comparatively low cost for manufacture a simple, effective, and compact device composed of few parts, not liable to derangement, adapted to be adjusted to compensate for wear, and particularly constructed with reference to convenience of use in a wide range of situations.

With these ends in view my invention consists in an inside and outside micrometergage having certain details of construction, as will be hereinafter described, and pointed out in the claim.

Inv carrying out my invention as herein shown I employ two disk-shaped measuring members A and A', which on account of their form I shall for convenience hereinafter speak of as measuring-disks, the inner, as well as the outer, faces of these disks being These two disks exactly correspond in diameter, as shown, and while I conceive that they might sain No. 678,361. (Nb model.)

be dierentiated in diameter somewhat it is probable that the best'resnlts will be secured by forming them of the same or approximately the same diameter. The disk A is located upon and by preference formed integral with the outer end of a cylindrical bar or stem B, which in turn is formed integral with the measuring-screw B', while the disk A' is located at the outer end of and preferably 6o formed integral with the graduated sleeve C, the inner end of which is formed with screwthreads C', which receive the threads of the measuring-screw B. For the purpose of compensating for wear the inner end of the said sleeve is formed with a narrow slit C2, which permits the said end of the sleeve to be slightly contracted by means of a slightly-tapered compensating nut D, corresponding in external diameter to the external `diameter of the 7o sleeve and internally threaded, so as to be screwed upon an externally-threaded slightlytapered neck C3, formed by reducing in diameter and threading the extreme inner end of the sleeve. I do not, however, limit myself to this mode of taking up wear between the sleeve and the measuring-screw. The said screw is inclosed by a rotatable thimble E, having its inner end beveled, as at E', and graduated, as shown in Fig. 1, the said inner 8o end of the thimble passing over the inner end of the sleeve C and the nut D. The said thimble is coupled at its outer end with the end of the measuring-screw'B' by means of a binding-screw comprising a knurled or other- 8 5 wise roughened handle F, an expanding sepa'- rating-bevel F', and a threaded stem F2. The outer end of the said sleeve is formedwith a heavy solid head E2, formed with a smooth central opening or bar E3, which receives a 9o smooth neck B2, formed at the extreme outer end of the( measuring-screw, which is also formed with a screw-hole B3, the said neck B2 fitting friction-tight into the opening E3. To permit the said neck to be'expanded in the 95 said openin g, itis formed with a slit B4, which enables the neck to be expanded by the expanding-bevel F' of the binding-screw, the stem F2 of which enters the screw-hole B3 and through the medium of which the sleeve and roo screw are coupled together, so as to operate virtually as one piece. In case of wear the binding-screw may be reversed or backed out of the measuring-screw sufficiently to permit the thimble to be rotated with respect to the screw, after which the parts are recoupled again.

By reference to Fig. l it will be seen that the sleeve C is formed with two parallel scales G and G', both of which are read in conjunction with the grad nations formed upon the bevel E of the thimble. The scale G, which is the upper scale, as shown, is employed for making outside measurements,while the scale G', which is the lower scale, as shown, is employed for making inside measurements. It will be noticed that the said scale G begins at its outer end to read eight-tenths, instead of ten-tenths, and this is for the reason that in inside measurements the thickness of the two measuring-disks has to be taken into consideration, so that when each of them is one- Itenth of an inch thick two-tenths of an inch must be discounted for their combined thickness, but of course the disks may vary in thickness; but whatever their combined thickness is it must be accounted for in the graduation of the scale G.

For the purpose of facilita ing the manipulation of the device the disk A', which is held againstrotation with the sleeve E while the measuring-screw, and hence the disk A, is being rotated, is formed with two roughened lugs d a, which permit it to be rigidly grasped and held.

It is apparent that in carrying out my invention some changes in the construction shown and described may be made, and I would therefore have it understood that I do not limit myself to the exact construction herein described, but hold myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of my invention.

Having fully described myinvention, what I claim as new, and desire to secure by Letters Patent, is-

In a micrometer-gage,the combination with a graduated sleeve, of a measuring-disk 1ocated at the outer end thereof, a measuringscrew passing through the said sleeve, a corresponding `disk located at the projecting outer end of the said screw, a thimble coupled with the opposite end of the screw and embracing the said sleeve over which it moves when the screw is rotated in one direction or the other, the said measuring-disks being larger in diameter than the said sleeve and screw, and having their outer portions unobstructed and their inner faces adapted for outside measurements, and their outer faces adapted for inside measurements.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

GEORGE J. LAVIGNE. Vituesses:

FRED. C. EARLE, LILLIAN D. KELSEY. 

